This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A371693 #14 Nov 24 2024 08:26:28
%S A371693 1,4,28,248,2480,26688,301648,3531424,42449088,520858496,6497190528,
%T A371693 82146802944,1050370074624,13559126110720,176469550681344,
%U A371693 2313050095245824,30506619439926272,404558181197010944,5391161355764205568,72156618656648237056,969557980700415827968
%N A371693 G.f. satisfies A(x) = ( 1 + x * A(x) * (1 + A(x)) )^2.
%F A371693 G.f.: B(x)^2 where B(x) is the g.f. of A219534.
%F A371693 a(n) = Sum_{k=0..n} binomial(n,k) * binomial(2*n+2*k+2,n)/(n+k+1).
%o A371693 (PARI) a(n, r=2, t=2, u=2) = r*sum(k=0, n, binomial(n, k)*binomial(t*n+u*k+r, n)/(t*n+u*k+r));
%Y A371693 Column k=2 of A378239.
%Y A371693 Cf. A006318, A371681.
%Y A371693 Cf. A219534.
%K A371693 nonn
%O A371693 0,2
%A A371693 _Seiichi Manyama_, Apr 03 2024